Barcelona's Lionel Messi (C) controls the ball against Valencia's Gago during their Spanish first division soccer match against Valencia at Nou Camp stadium in Barcelona September 2, 2012.

Barcelona vs AC Milan takes place in the Champions League on Tuesday night with the Spanish La Liga side for once considered underdogs having lost the first leg in Milan 2-0. The game will kick off at 7.45 p.m. UK time (3.45 p.m. ET) and can be watched online through live stream (details below).

Barcelona's storming La Liga form has sparked many to consider them overwhelming favorites to win the Champions League this season. Messi has been on fire, with 51 goals in just 41 games in all competitions this season (including 5 in the Champions League), and his form had further made many to consider this season's top European competition to be little more than a formality for Barcelona.

However, AC Milan turned many predictions on their heads in the first leg, completely outplaying Barcelona, and for once neither Messi nor any of their scores of attacking talent looking like scoring for the entire 90 minutes on the pitch. At every turn they were repelled by the organized rock solid defense of their Italian counterparts.

Coming to the Nou Camp trailing by two goals, and without an away goal to their name, in most people's eyes would make Barcelona underdogs. If Milan manage to score even one goal then Barcelona would need four. However, if there is one team in the world that you'd bet on being able to turn a tie so impeccably on its head it would be Barcelona.

Iniesta has insisted that the deficit is not impossible to come back from: "It will be difficult but not impossible. We have to play as if it was a final. That's what our mentality needs to be from the first minute to the last."

(Photo: Reuters/Stefano Rellandini)

AC Milan's Stephan El Shaarawy shoots and scores against Cagliari during their Serie A soccer match at San Siro stadium in Milan, September 26, 2012.

History is against Barcelona; no team has ever come back from being two goals down from the first leg unless they have had an away goal to rely upon. But that said, this Barcelona side is used to making their own history.

Surprisingly form is not with Barcelona as well. Despite them going almost the entire season until now without losing a domestic game in Spain, they have lost twice to arch rivals Real Madrid in recent weeks, as well of course as that bad defeat in Italy.

Three losses in such a short space of time is not what this Barcelona team is used to, and it should be a fantastic game to watch to see if they can respond accordingly, or whether AC Milan will once again be able to stifle Messi and co.

The game is scheduled to kick off at 7.45 p.m. UK time and can be watched online through live stream by clicking here.